Brain Hamorrhage

Asked for Female, 29 Years

My elder sister was completely fine till one night before she suffered through an ugliest headache in morning. She was unable to walk, talk and use her left part of body. Right now she is under observation in ICU. Doctors told to wait for 4 days before undertaking any operation. Could I please know how serious she might get. Will she recover? Is brain hamorrhage curable?